Lennox Split & Multi-Split

Lennox Error Code E423

Split & Multi-Split: Air conditioner (outdoor), Heat pump (outdoor)

What It Means

  • The inverter has detected a circuit problem.

Causes & actions from Lennox

How it shows
  • Inverter code: 40
  • Inverter LED flash code: Red 4 flashes, Green OFF (green: off, red: flashing ×4)
  • Outdoor control 7-segment display: E423

Control locks out after 10 strikes within an hour. To clear, disconnect power to the indoor unit (24VAC power source to the outdoor control) which will power off the outdoor control and will open the outdoor unit contactor, which interrupts power to the inverter and then re-apply power.

Other manual wording

EL18XCV, EL18XCV-024, EL18XCV-036, EL18XCV-048, EL18XCV-060, EL18XPV, EL18XPV-024, EL18XPV-036, EL18XPV-048, EL18XPV-060, EL19KPV,…

Control will lock out after 10 strikes within an hour. To clear, disconnect power to the indoor unit (24VAC power source to the outdoor control) which will power off the outdoor control and will open the outdoor unit contactor, which interrupts power to the inverter and then re-apply power.

Applicable models & manual sources
  • EL18XCV

    The inverter has detected a circuit problem.

    EL18XCV, EL18XCV-024, EL18XCV-036, EL18XCV-048, EL18XCV-060

    EL18XCV manual, page 37

  • EL18XPV

    The inverter has detected a circuit problem.

    EL18XPV, EL18XPV-024, EL18XPV-036, EL18XPV-048, EL18XPV-060

    EL18XPV manual, page 37

  • EL19KPV

    The inverter has detected a circuit problem.

    EL19KPV, EL19KPV-024, EL19KPV-036, EL19KPV-048, EL19KPV-060

    EL19KPV manual, page 43

  • EL21KLV

    The inverter has detected a circuit problem.

    EL21KLV, EL21KLV-024, EL21KLV-036, EL21KLV-048, EL21KLV-060

    EL21KLV manual, page 46

  • EL22KCV

    The inverter has detected a circuit problem.

    EL22KCV, EL22KCV-024, EL22KCV-036, EL22KCV-048, EL22KCV-060

    EL22KCV manual, page 40

  • SL22KLV

    The inverter has detected a circuit problem.

    SL22KLV, SL22KLV-024, SL22KLV-036, SL22KLV-048, SL22KLV-060

    SL22KLV manual, page 43

  • SL25KCV

    The inverter has detected a circuit problem.

    SL25KCV, SL25KCV-024, SL25KCV-036, SL25KCV-048, SL25KCV-060

    SL25KCV manual, page 37

  • SL28XCV

    The inverter has detected a circuit problem.

    SL28XCV, SL28XCV-024, SL28XCV-036, SL28XCV-048, SL28XCV-060

    SL28XCV manual, page 31

  • EL18XCV

    The inverter has detected a circuit problem.

    EL18XCV, EL18XCV-024, EL18XCV-036, EL18XCV-048, EL18XCV-060

    EL18XCV manual, page 76

  • EL18XPV

    The inverter has detected a circuit problem.

    EL18XPV, EL18XPV-024, EL18XPV-036, EL18XPV-048, EL18XPV-060

    EL18XPV manual, page 79

  • EL19KPV

    The inverter has detected a circuit problem.

    EL19KPV, EL19KPV-024, EL19KPV-036, EL19KPV-048, EL19KPV-060

    EL19KPV manual, page 81

    EL19KPV manual, page 81

  • EL21KLV

    The inverter has detected a circuit problem.

    EL21KLV, EL21KLV-024, EL21KLV-036, EL21KLV-048, EL21KLV-060

    EL21KLV manual, page 93

  • EL22KCV

    The inverter has detected a circuit problem.

    EL22KCV, EL22KCV-024, EL22KCV-036, EL22KCV-048, EL22KCV-060

    EL22KCV manual, page 76

  • SL22KLV

    The inverter has detected a circuit problem.

    SL22KLV, SL22KLV-024, SL22KLV-036, SL22KLV-048, SL22KLV-060

    SL22KLV manual, page 86

  • SL25KCV

    The inverter has detected a circuit problem.

    SL25KCV, SL25KCV-024, SL25KCV-036, SL25KCV-048, SL25KCV-060

    SL25KCV manual, page 71

  • SL28XCV

    The inverter has detected a circuit problem.

    SL28XCV, SL28XCV-024, SL28XCV-036, SL28XCV-048, SL28XCV-060

    SL28XCV manual, page 65

Disclaimer: This information is for general reference. Code wording and instructions vary by model. Always follow the service manual for your exact unit.

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